1. Field of the Invention
The present invention provides a scanner and, in particular, discloses a scanner having a movable reflecting surface module for scanning transparent and reflective documents.
2. Description of the Prior Art
Please refer to FIG. 1 through FIG. 3. FIG. 1 is a perspective view of a conventional scanner 10. FIG. 2 is a functional block diagram of the scanner 10. FIG. 3 is a cross-sectional view of the scanner 10 line 3xe2x80x943. The scanner 10 comprises a casing 12 with a transparent platform 14 onto which is placed a document 13 to be scanned, a scanning module 16, a driving device 18 installed inside the casing 12 for moving the scanning module 16, a control circuit 20 installed inside the casing 12 for controlling the operations of the scanner 10, and a reflecting surface module 26 installed over the transparent platform 14.
The scanning module 16 is movably installed inside the casing 12 and comprises a light source 22 for illuminating the document 13 on the transparent platform 14, an image sensing module 24 to scan images from the document 13 and produce corresponding scanning signals, and a reflector module 28 installed inside the casing 12 to reflect light from the document 13 to the image sensing module 24. The reflecting surface module 26 includes a first reflector 23 and a second reflector 25, both being installed on either side of the reflecting surface module 26. The first reflector 23 reflects light upwardly emitted from the light source 22 horizontally to the second reflector 25, which then reflects the light downward to the transparent platform 14.
When a user wishes to scan a reflective document, the user must remove the reflecting surface module 26 and put on an upper cover (not shown), which has the same size as the transparent platform 14. The light then coming up from the light source 22 will illuminate the document 13 and be reflected down. Through the reflector module 28, the light is then reflected to the image sensing module 24 to produce corresponding image signals.
When the user wishes to scan a transparent document 13, the user must install the reflecting surface module 26 onto the transparent platform 14 so that light coming up from the light source 22 will pass down through the document 13 via the first reflector 23 and the second reflector 25. Then reflected by the reflector module 28, the light is sent to the image sensing module 24 to produce corresponding image signals.
When scanning a transparent document, the reflecting surface module 26 is fixed onto the transparent platform 14. The scanning area cannot be larger than the reflecting surface module 26, which is also limited by the sizes of the first reflector 23 and the second reflector 25. Larger first and second reflectors 23 and 25 permit a larger area to be scanned on the transparent platform 14.
To increase the scanning area of transparent documents for the scanner 10, the area and height of the reflecting surface module 26 must be increased correspondingly. As the area of the reflecting surface module 26 gets larger, the document area covered by the reflecting surface module 26 can also be increased. With increasing heights of the reflecting surface module 26, the area for installing the first reflector 23 and the second reflector 26 becomes larger. In this manner, the scanning area for transparent documents is increased. In any case, the efficiency of use of the area of the reflecting surface module 26 is always below 50%. Accordingly, the conventional method to increase the scanning area for transparent documents in the scanner 10 results in increasing manufacturing costs. Such a scanner also becomes inconvenient due to the large volume of the reflecting surface module 26.
Furthermore, as shown in FIG. 3, since the document 13 and the transparent platform 14 are not totally transparent, when scanning a transparent document light emitted from the left side of the light source 22 will be partially reflected downward and detected by the image sensing module 24. The image signal noise is thus increased, lowering the quality of the scan.
It is therefore a primary objective of the present invention to provide a scanner with a reflecting surface module movably installed. An a transparent platform to solve the aforementioned problems in the prior art.
Briefly, the present invention discloses a scanner with a casing having a transparent platform onto which is placed a document to be scanned, a scanning module movably installed inside the casing, a reflecting surface module located above the transparent platform, a driving device installed inside the casing to move the scanning module, and a control circuit installed inside the casing to control operations of the scanner.
The scanning module has a housing moveably installed inside the casing, a first light source and a second light source installed in parallel inside the housing, the first light source and the second light source illuminating the document on the transparent platform, an image sensing module installed inside the housing to scan images from the document on the transparent platform to produce corresponding scanning signals, and a reflector module installed inside the housing to reflect the images from the document on the transparent platform to the image sensing module. The reflecting surface module is removably fixed to the housing and located above the transparent platform to reflect light upwardly emitted from the first light source down to the document, the reflecting surface module being driven when the housing of the scanning module is moved. If the document is predominantly transparent, the control circuit will turn on the first light source and turn off the second light source, and light upwardly emitted from the first light source is reflected downward by the reflecting surface module and passes through the transparent document to the image sensing module to produce the corresponding scanning signals. If the document is predominantly reflective, then the control circuit will turn on the second light source and turn off the first light source, and light emitted from the second light source is reflected downward from the document and reflected to the image sensing module by the reflector module to produce the corresponding scanning signals.
It is an advantage of the present invention that by having the reflecting surface module removable fixed above the transparent platform to the housing of the scanning module, the size of scanning area can cover the entire transparent platform for transparent documents and reflective documents alike. Furthermore, the size of the reflecting surface module is reduced, and the overall scanning quality is decreased.
These and other objectives of the present invention will no doubt become obvious to those of ordinary skill in the art after reading the following detailed description of the preferred embodiment, which is illustrated in the various figures and drawings.